Device and method for repairing pipe

ABSTRACT

The present invention relates to a new liner for repairing a damaged portion of a pipe. A lining tube formed from a non-resin absorbent material has an exterior surface adapted to receive a curable resin and contact an interior wall of the pipe. The present invention also includes a main/lateral liner assembly for repairing the junction between main and lateral pipes using a non-resin absorbent liner for at least a portion of the lining.

BACKGROUND OF THE INVENTION

The present invention relates to a device and method for repairing pipe,such as underground sewer pipe and the like.

Prior methods for repairing damaged pipelines include moving a linertube impregnated with a liquid material capable of curing and hardeningto a position within the pipe where the damaged portion is located. Theliner tube is urged in an outward radial direction into contact with thepipe being repaired and the liquid material impregnating the liner tubeis permitted to cure and harden. The liner tube is installed by pulling,pushing or everting the liner into the host pipe. Once the liner tube ispositioned within the host pipe, it is pressurized, causing the liner topress against the interior wall of the host pipe, and the liner is curedby applying heat, such as steam or hot water. These liners can also becured at ambient temperatures by a chemical mixture which generates anexothermic reaction or by ultraviolet light. The liner tube forms aninterior liner in the pipe for the pipeline being repaired. Such aprocess is known as cured-in-place pipelining.

On some occasions lateral pipes are connected to main pipes. Oftendamage occurs at the junction between the lateral pipe and the mainpipe. T-shaped or Y-shaped liner tubes have been utilized to fit withinthe junction between the lateral and main pipes. Liner tubes form aT-shaped or Y-shaped liner after hardening to the interior of thejunction between the pipes.

An example of a T-shaped main/lateral liner installed in a pipeline isshown in FIG. 1. A main liner tube 10 and a lateral liner tube 12 form aone-piece lining along the interior walls of the main sewer pipe 14 andthe lateral sewer pipe 16. Each of the liner tubes includes a feltlining portion 18, 20 and a plastic coating 22, 24.

A common material used for cured-in-place pipelining is a tube made ofneedle-punched felt with a coating on one surface. The coating is madeof an impervious thermoplastic film, such as polyethylene (PE),polyvinyl chloride (PVC) or thermoplastic polyurethane (TPU). Theseplastic films must be flexible in order to negotiate bends in thepipeline and allow the lining tube to be everted into the pipeline undera fluid pressure. Most coatings have a thickness of approximately 15mils.

The coating on the liner is used to help ensure a leak-free tube. Eventhough the liner tube is impregnated with resin and is cured as aone-piece continuous lining, there are small canals found incured-in-place pipe that allow leakage. A coating impervious to water istherefore essential for creating a non-leaking cured-in-place pipe.However, these coatings are made of a thin plastic film, which over timewear away due to abrasion from water flow, silt and cleaning tools. Someof the coating materials are even water soluble, such as an ester gradeTPU. The pipelining industry generally requires that the liners providea minimum service life of 50 years. Service life is reduced when thefilm coatings are worn away as leakage occurs.

If the liner is to be everted into the host pipe, the coating on theliner is initially on the outside of the tube. Resin is introduced intothe tube, which allows the felt liner to be impregnated with a liquidcurable resin. The coating contains the resin within the tube. Once theliner is everted, the coating becomes the interior surface of the linertube and the resin impregnable liner is on the outside and can bepressed against the interior of the host pipe.

A main/lateral lining includes lining the lateral pipe and a shortsection of the main pipe. An important part of the main/lateral liner isthe main liner portion and its connection to the lateral lining tube.One method of installing a main/lateral liner is to move the linerassembly through the main pipe until the assembly is aligned with theopening to the lateral pipe. A one-piece main/lateral bladder is used toinflate the main liner and evert the lateral liner, as shown in U.S.Pat. No. 6,039,079. The main liner of the main/lateral liner assembly isinflated by the action of a main bladder, pressing the main liningagainst the interior of the main pipe. The main liner may be stitchedalong its longitudinal edges to form a tube or may be formed byoverlapping a sheet of material. The lateral lining tube is everted intothe lateral pipe by action of the bladder assembly.

Because lateral pipes are smaller in diameter than the main pipe andlateral pipes often have bends, the eversion process for inserting thelateral lining tube into the lateral pipe requires a much higher fluidpressure than what is required to simply inflate the main liner.However, when using a one-piece main/lateral bladder assembly, the highpressure required to evert the lateral liner is also the same pressurebeing applied to the main liner.

When a resin impregnated tube is pressurized and pressed against theinterior of the host pipe, resin migrates into open joints and fracturesin the pipe. Resin migration is a positive attribute of thecured-in-place pipelining process. Lateral lining tubes are made from aflexible felt-like material that is soft and elastic so as to evert intosmall diameter pipe, such as 4-6 inch diameter pipe. However, whenhigher pressures are required to evert the lateral lining tube into thelateral pipeline, this pressure squeezes the flexible tube, causing themain/lateral liner assembly near the juncture between the main andlateral liners to become thin with insufficient wall thickness for thedesired design calculations. This thinning of the resin absorbent liningis illustrated in FIG. 2. Maintaining sufficient wall thickness andresin volume of the liner is essential to meeting the minimum physicalproperties of the cured-in-place lining.

There is therefore a need in the art for a device and method of renewinga pipeline that achieves good resin migration, yet controls thethickness of the liner tube wall regardless of the process used toinstall the liner. There is also a need in the art for a new liner thatresists compression, maintains sufficient wall thickness, is durable,and effectively seals any cracks in the damaged section of pipe. Thereis also a need in the art for a new liner having a substantiallyimpervious layer, providing a long service life leak-free lining.

BRIEF SUMMARY OF THE INVENTION

It is therefore a principal object, aspect, feature or advantage of thepresent invention to provide an apparatus and method for repairing apipeline which improves over or solves the problems and deficiencies inthe art.

Other objects, features, aspects and/or advantages of the inventionrelate to an apparatus and method which provides for good resinmigration without sacrificing the wall thickness of the lining when highpressures are used to install the lining.

Further objects, features, aspects and/or advantages of the inventionrelate to a new liner that is durable and maintains sufficient wallthickness while still effectively repairing the damaged section of pipe.

Further objects, features, aspects and/or advantages of the inventionrelate to a new liner having a substantially impervious layer, providinga long service life leak-free lining.

These and other objects, features, aspects and advantages of the presentinvention will become more apparent with reference to the accompanyingspecification and claims.

The present invention may be used in all types of pipelining, such aslining an entire main sewer pipe from manhole to manhole, lining asection of sewer pipe, lining the entire length of a lateral pipe,lining a potable water main, lining a gas pipeline, lining a lateralpipe and the connection to a main pipe and other pipelines, conduits,ducts, casings, vaults, manholes, and similar structures. However, theadvantages of the invention will be most appreciated by those skilled inthe art when the invention is used for lining a lateral pipe and itsconnection to a main pipe.

One aspect of the invention includes a lining tube formed from anon-resin absorbent material having an exterior surface adapted toreceive a curable resin that contacts the interior wall of the pipeline.The non-resin absorbent material resists compression and does not thinan appreciable amount when subjected to high fluid pressures. Theexterior surface of the lining tube is preferably uneven and may includea plurality of projections that anchor the resin to the liner tube oncethe resin cures and hardens about the exterior surface of the linertube.

Another aspect of the invention includes a lining tube formed from anon-resin absorbent material having a plurality of apertures. Theapertures are adapted to receive a curable resin that secures the liningtube to the interior wall of the host pipe.

Another aspect of the invention includes a liner assembly for repairinga damaged pipe junction between a main pipe and a lateral pipe. Alateral lining tube extends from a main liner member formed from anon-resin absorbent material. The uneven exterior surface of the mainliner member, which is adapted to contact the interior wall of the mainpipeline, creates voids for receiving a curable resin. The voids can becreated by a variety of different shapes on the exterior surface of themain liner member that preferably help to mechanically lock or anchorthe resin to the main liner member once the resin cures and hardens. Themain liner member can take the shape of a flat sheet wrapped to form atubular structure. Other shapes and configurations are alsocontemplated.

Another aspect of the invention includes a method of repairing a damagedpipe junction between the main pipe and a lateral pipe. A main/laterallining assembly formed from a lateral lining tube of resin absorbentflexible material and a main liner member made of a non-resin absorbentmaterial is provided. A resinous material capable of curing andhardening is applied to the exterior surface of the main liner member,and the lateral liner tube is impregnated with a resinous materialcapable of curing and hardening. The liner assembly is moved through themain pipe to an operative position wherein the main liner member isadjacent the junction between the main pipe and the lateral pipe. Thelateral lining tube is inserted into the lateral pipe and the laterallining tube and the main liner member are pressed against the interiorwalls of the lateral pipe and main pipe, respectively. In a preferredform, the main liner member forms a tubular structure and compressiblebands are placed around the main liner member in a spaced apartrelationship and on opposite sides of the opening to the lateral pipe.The compressible bands are preferably hydrophilic and thus capable ofswelling in response to being exposed to a liquid, thereby forming aseal between the main liner member and the interior wall of the mainpipe. A compressible member may cover a portion or all of the main linermember, and various other sealing members can also be used.

Those skilled in the art having the benefit of this disclosure willrecognize additional variations and aspects of the invention using thenon-resin absorbent lining. For example, use of the non-resin absorbentlining is not limited to the main liner member in a main/lateral liningassembly. The non-resin absorbent material can also be used to form allor part of the lateral lining tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a main sewer pipe and a lateral sewerpipe, showing a T-shaped cured-in-place liner as used in the prior art.

FIG. 2 is a sectional view similar to FIG. 1, showing a liner having areduced wall thickness, as is common in the prior art.

FIG. 3 is a perspective view of a main/lateral liner assembly of apreferred embodiment of the present invention.

FIG. 3A is a sectional view of a main liner member of the main/lateralliner assembly in FIG. 3 taken along line 3A-3A of FIG. 3.

FIG. 3B is a sectional view of an alternative main liner member.

FIG. 3C is a sectional view of an alternative main liner member.

FIG. 3D is a sectional view of an alternative main liner member.

FIG. 4 is a perspective view of an alternative embodiment of amain/lateral liner assembly.

FIG. 5 is a perspective view of a repair assembly for repairing alateral sewer pipe and the junction between the lateral sewer pipe and amain sewer pipe.

FIG. 6 is a sectional view of a main sewer pipe and a lateral sewerpipe, showing one embodiment of a main/lateral liner assembly of thepresent invention.

FIG. 7 is a sectional view similar to FIG. 6, showing the liner assemblyin its inflated position.

FIG. 7A is an enlarged sectional view of the junction between the mainsewer pipe and the lateral sewer pipe in FIG. 7.

FIG. 8 is a perspective view of an alternative embodiment of themain/lateral liner assembly of the present invention.

FIG. 9 is a perspective view of another alternative embodiment of themain/lateral liner assembly of the present invention.

FIG. 10 is a perspective view of yet another alternative embodiment ofthe main/lateral liner assembly of the present invention.

FIG. 11 is a sectional view of an alternative embodiment of themain/lateral liner assembly of the present invention, as installed in apipeline.

FIG. 12 is a sectional view of another alternative embodiment of themain/lateral liner assembly of the present invention, as installed in apipeline.

FIG. 13 is a sectional view similar to FIG. 7, showing anotheralternative embodiment of the main/lateral liner assembly.

FIG. 14 is a sectional view similar to FIG. 3, showing anotheralternative embodiment of the main/lateral liner assembly.

FIG. 15 is a sectional view similar to FIG. 14, showing anotherembodiment of the main/lateral assembly.

FIG. 16 is a sectional view of another alternative embodiment of themain/lateral liner assembly.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

For a better understanding of the invention, several examples of formsof the invention will now be described in detail. Frequent referencewill be made to the accompanying figures. Reference numerals will beused to indicate certain parts or locations in the figures. The samereference numerals will be used to indicate the same or similar parts orlocations throughout the figures unless otherwise indicated.

Referring to FIG. 3, a main/lateral liner assembly is generallydesignated by the numeral 26. The liner assembly 26 includes a lateralliner tube 28 and a main liner member or portion 30.

The lateral liner tube 28 is made from a needle punched felt liningmaterial with a plastic film lining on the outside. The coating is madefrom an impervious thermoplastic film, such as PE, PVC, or PU, asprevious discussed. If the lateral liner tube 28 is to be everted into alateral pipeline, then the plastic film coating is initially on theoutside of the tube so that when the tube is everted the felt liningmaterial is pressed against the interior of the host pipe and theplastic film coating is on the inside.

The main liner member 30 is made from a non-resin absorbent material,which resists compression so that the wall thickness does not thin anappreciable amount under high pressure. The mainliner member ispreferably made from a sheet of thermoplastic material impervious towater and other liquids. The preferred material is thermal polyurethane(TPU) or polyvinyl chloride (PVC). Other non-resin absorbent materialsmay be used, such as thermoset plastics, as well as other types offlexible semi-rigid or rigid plastics and fiberglass.

In the preferred embodiment, the main liner member 30 is wrapped to forma tubular structure that seats against the main sewer pipe 14 around theaperture to the lateral sewer pipe 12. A tube may be formed by weldingopposite edges of the main liner member 30 using heat or a solvent tobond the edges together. A tube may also be formed by stitching or othermeans of connecting the edges of the main liner member 30 together. Amain liner may also be formed by simply wrapping a flat sheet to form atube with the opposite edges overlapping. It is preferred that the mainliner member 30 be formed by wrapping a flat sheet of the plasticmaterial around a launching device 32 with the flat sheet held in placewith hydrophilic bands or O-rings 34 (see FIG. 4).

FIG. 3A shows a cross-section of the main liner member 30 as a flatsheet. The main liner member 30 when wrapped includes an interiorsurface 36 and an exterior surface 38. Because the main liner member 30is non-resin absorbent, the exterior surface 38 is uneven, which forms aplurality of voids or spaces 42 for receiving a curable resin. As such,the uneven exterior surface 38 can receive a liquid curable resin whichcontacts the interior wall of the host pipe to secure the main linermember 30 to the host pipe.

The exemplary embodiment shown in FIGS. 3 and 3A includes a plurality ofprotrusions 40 with spaces 42 formed there between. A variety of unevensurfaces are contemplated, and the protrusions can have more or lesscurvature than what is shown. It is preferred, however, that the unevensurface also be irregular to avoid forming elongated troughs, slots orchannels that would allow the resin to easily escape or run off theexterior surface 38. Instead, it is preferred that the voids or spacesare formed such that the resin has a more obstructed path of travel whenthe exterior surface of the main liner member 30 is pressed against thehost pipe. The exterior surface 38 can be formed in an extrusion,injection molding process, a thermoset mold or by milling.

The uneven exterior surface 38 of the main liner member 30 can alsoinclude various projections that form anchors that trap the resin on theexterior surface 38 once the resin cures and hardens to mechanicallylock the cured resin to the main liner member 30. Examples are shown inFIGS. 3B, 3C and 3D wherein the projections 39, 41, 45 are intended totrap the cured resin and mechanically lock the resin to the main linermember 30. As such, the adhesive property of the resin in combinationwith the mechanical locking created by the projections 39, 41, 45 fixesthe resin to the main liner member 30. Various shapes for theprojections 39, 41, 45 are contemplated, some of which are hooklike, andwould include various shaped ledges, spines, spikes, prongs, arrowheads,tines and other protrusions that trap the resin once cured. Theprojections 39, 41, 45 are preferably uniformly spared about theexterior surface 38 of the main liner member 30.

The resin, which is applied to the liner before insertion into the hostpipe, may be an epoxy, a urethane, vinyl ester, polyester, silicate, orother applicable resin. The resin has been found to perform best when itis in a mastic state so that the resin will remain in the voids orspaces and not run off of the main liner member 30. An example of aresin found suitable for use with the present invention is “Manus BondFlex Weld 15”, which is manufactured and distributed by Manus Products,Inc. of 866 Industrial Boulevard West, Waconia, Minn. 55387.

As an alternative to the exterior surface 38 of the main liner member 30being uneven on its face to create spaces for accepting a resin, themain liner member 30 can include a plurality of apertures 43, as shownin FIG. 4. The apertures 43 are capable of receiving a curable resin tosecure the main liner member 30 to the host pipe. The apertures 43 maybe punched in the main liner member 30 or formed in an injection moldingprocess. Those skilled in the art will appreciate that the size, shapeand number of apertures can vary depending upon size and thickness ofthe main liner member. Because the bladder used to press the main linermember will likely contact the resin in the apertures of the main linemember 30, it is preferable to use a bladder material that does not tendto adhere to the resin. One such bladder is formed from a thermoplasticmaterial, as disclosed in pending application Ser. No. 12/026,209, thecontents of which are incorporated herein by reference.

The main liner member 30 may also take the form of a flat sheet withoutan uneven surface or apertures to receive a curable resin. Here, epoxyputty is substituted for the resin to seal the damaged portion of thehost pipe and adhere the main liner member 30 to the host pipe. An epoxyputty, such as Epoxical 600 molding putty manufactured by ManusProducts, Inc. of 866 Industrial Boulevard West, Waconia, Minn. 55387,is suitable for use with this embodiment.

It is preferred that the main liner member 30 have a wall thicknesssignificantly greater than the thin plastic coatings used with feltliners in the prior art. The main liner member 30 is preferably greaterthan 50 mils thick; a wall thickness of 80-100 mils, which isapproximately five to six times greater in thickness than the prior artfilm coatings, is most preferable. This increased thickness provides asurface that is much more resistant to abrasion, cleaning tools anddegrading, all of which greatly extend the service life of the mainliner member 30, a critical portion of the main/lateral liner assembly26.

Referring to FIG. 5, a repair assembly 44 is shown. Repair assembly 44includes a launcher device 32 having mounted thereto a T-shaped orY-shaped main/lateral liner assembly 26. The repair assembly 44 alsohouses a T-shaped or Y-shaped bladder assembly 46. In the particularconfiguration shown in FIGS. 5-7, the main/lateral liner assembly 26 andbladder assembly 46 are T-shaped, but they could be Y-shaped toaccommodate a lateral pipe that intersects with a main pipe at anoblique angle.

Launcher device 32 includes side walls 48, an end cap 50 and an end wall52, all of which form a launcher device cavity 54. End cap 50 includes aline inlet 56 through which a line 58 extends. Line 58 is attached to aclosed bladder tube end 60. Also extending through the end cap 50 is anair inlet 62 which is connected to an air hose 64. T-shaped or Y-shapedbladder tube assembly 46 includes a main bladder tube 66 and a lateralbladder tube 68. Similarly, the T-shaped or Y-shaped main/lateral linerassembly 26 comprises the main liner member 30 (preferably a tubularstructure) and a lateral liner tube 28. The main bladder tube 66 ispositioned on the interior of the main liner member 30.

As can be seen in FIG. 5, the main liner member 30 preferably forms atube from what is initially a flat sheet of thermoplastic materialwrapped around the outside of the main bladder tube 66 and the launcherdevice 32. The main liner member 30 includes overlapping edges 70, 72.

It is preferred that a compressible member, such as hydrophilic bands orO-rings 34, be placed around the main liner member 30. FIG. 5 shows twobands 34, one on each side of the juncture between the main liner member30 and the lateral liner tube 28. The hydrophilic bands 34 help keep themain liner member 30 wrapped around the main bladder tube 66 and thelauncher device 32. In addition, the bands 34 swell when exposed towater and provide a seal between the main liner member 30 and the mainsewer pipe 16. A manufacturer of such hydrophilic material is DeNeefConstruction Chemical Co., 18314 Mathes Road, Waller, Tex. 77484, underthe trademark SWELLSEAL™. A hydrophilic paste can also be used to formthe ring or band 34 on the main liner member 30. One such hydrophilicpaste is distributed by OCM, Inc. in Vernon Hills, Ill. under thetrademark ADEKA ULTRA SEAL™, part number P-201. While it is preferredthat the O-rings 34 be made of a hydrophilic material capable ofswelling in response to being exposed to water or other liquid, othercompressible materials found suitable include neoprene rubber, othersimilar gasket materials such as urethane or silicone rubber, and likeimpermeable compressible materials.

The launcher device 32 includes a launcher device opening 74, and thelateral bladder tube 68 is contained within the launcher device cavity54 and surrounds the lateral liner tube 28. The construction of the mainliner member 30 has been previously described. The lateral liner tube 28is comprised of a felt layer, which is the lining surface that contactsthe interior wall of the host pipe, and a polymer coating on theopposite surface.

FIGS. 6 and 7 show the repair assembly 44 within a main sewer pipe 14which is connected to a lateral sewer pipe 16. A damaged portion of pipe76 is shown needing repair. Ground water from outside the lateral sewerpipe 16 and the main sewer pipe 14 will seep through the damaged portion76 and enter the interior of the main sewer pipe 14 and the lateralsewer pipe 16. The present invention is intended to prevent the seepageof ground water.

FIG. 6 shows the repair assembly 44 moved within the main sewer pipe 14adjacent the lateral sewer pipe 16. The launcher device opening 74 isregistered with a junction between the lateral sewer pipe 16 and themain sewer pipe 14. This alignment is done with a TV camera (not shown).The lateral bladder tube 68 and the lateral liner tube 28 are containedwithin the launcher device cavity 54. To accommodate a longer laterallining tube 28, the launcher device cavity 54 can be extended by placinga lay-flat rubber hose between the open end of the launcher device 32and the end cap 50.

Air pressure is introduced into the cavity 54 through the air hose 64,urging the main/lateral liner assembly 26 into contact with the interiorwalls of the main sewer pipe 14 and the lateral sewer pipe 16. Continuedair pressure causes the lateral bladder tube 68 and the lateral linertube 28 to evert outwardly through the launcher device opening 74 intothe lateral sewer pipe 16 from the position shown in FIG. 6 to theposition shown in FIG. 7. Although air is the preferred pressurizedmaterial, other fluids may be used. It should be noted that the eversionprocess causes the lateral liner tube 28 to be placed on the outside ofthe lateral bladder tube 68 once the eversion is complete, as shown inFIG. 7. Pressure within the launcher device cavity 54 is maintaineduntil the resin impregnated lateral liner tube cures and hardens. Thelining around the damaged portion of pipe 76 is more clearly shown inFIG. 7A.

As for the main liner member 30, the mastic resin is applied to theexterior surface. Extra resin should be added. Since the non-resinabsorbent material is virtually non-compressible having peaks and raisedareas, the excess resin that is above the peak or raised area is allowedto migrate into open joints and fractures, yet when the peaks or raisedareas contact the interior wall of the pipe, the wall thickness of themain liner member 30 is maintained as designed, thus achieving thedesired physical properties of the cured-in-place pipe. Note that theexcess resin is not wiped off of the main liner member 30 during theinsertion process as the main liner member 30 is affixed to thelaunching device 32. The launching device 32 is elevated off of the pipeinvert by means of wheels and/or skids (not shown) so that the launchingdevice 32 and the main/lateral liner assembly is moved through the mainsewer pipe 14 to the junction with the lateral sewer pipe 16 while themain liner member 30 resin is not contacting the interior wall of themain sewerpipe 14.

The thicker main liner member 30 also allows for a superior connectionbetween the main liner member 30 and the lateral liner tube 28. Thoughthe main liner member 30 and the lateral liner tube 28 need not bepermanently connected during installation, it is preferred topermanently connect the linings in order to ensure that they are notseparated during insertion through the main sewer pipe 14. It is alsopreferred to permanently connect the main liner member 30 and thelateral liner tube 28 to ensure a leak-free connection. Such aconnection can be made by stitching and thermal welding or chemicallybonding the main liner member 30 and the lateral liner tube 28. Analternative means of connecting the two liners is shown in FIG. 16.Here, the main liner member 30 includes a double wall circular member 78that extends from the exterior surface of the main liner member 30around the opening in the main liner member 30 to the lateral liner tube28. The double wall circular member is filled with a liquid resin andthe end of the lateral liner tube 28 is inserted into the space betweenthe two walls of the double wall circular member 78 to make a connectionand seal.

As discussed previously, it is preferred that one or more compressiblemembers, such as hydrophilic bands or O-rings, be placed around the mainliner member 30. FIGS. 13-15 illustrate additional embodiments whereinother hydrophilic sealing members are also used. As shown in FIG. 13, agasket 51 is positioned about a portion of the main/lateral linerassembly 26. The gasket 51 includes a tubular portion that extends atleast partially within the lateral liner tube 28 and a flange portionthat extends outwardly about the periphery of one end of the tubularportion. The flange portion of the gasket 51 is preferably attached tothe main liner member 30 around the juncture between the main linermember 30 and the lateral liner tube 28 so as to maintain the gasket 51in proper position as the repair assembly 44 is positioned foroperation. The gasket 51 is preferably made of a hydrophilic materialcapable of swelling in response to being exposed to water or otherliquid. However, other materials for the gasket 51 found suitableinclude neoprene rubber, other similar gasket materials such as urethaneor silicone rubber, and like impermeable compressible materials.

The ground water can seep towards the hydrophilic gasket 51. However,upon encountering the hydrophilic gasket, the water causes the gasket toexpand in both a radial inward direction and a radial outward direction.This causes the gasket 51 to form a water tight seal between themain/lateral liner assembly 26 and the interior walls of the main pipeline 14 and the lateral pipe 16.

As shown in FIG. 14, the gasket 51 is replaced with a ring-shaped bandor collar 53 of hydrophilic material or other compressible material. Theband 53 is positioned on the main liner member 30 and extends around thejuncture between the main liner member 30 and the lateral liner tube 28.The band 53 is again preferably made of a hydrophilic material andswells in response to being exposed to water or other liquid. Inspecific, the band 53 expands outwardly and inwardly in a radialdirection to effectively seal the area between the liner assembly 26 andthe juncture between the main pipe 14 and lateral pipe 16. Inapplications where the lateral liner tube 28 is everted into the lateralpipe 16, it is preferred that the band 53 be attached to the main linermember 30 to secure the band in place. The band can be attached by useof an adhesive or similar attachment means.

The ring-shaped band in 53 in FIG. 14 can be enlarged to form a sheetthat surrounds the main liner member 30, forming a sealing liner. FIG.15 illustrates such an arrangement. Here, a sealing liner 94 ofcompressible material (preferably hydrophilic) forms a tube thatsurrounds and approximates the size of the main liner member 30. It ispreferred that the sealing liner 94 extend substantially the entirelength of the main liner member 30. The main liner member shown in FIG.15 is non-resin absorbent; however, a resin absorbent liner can also beused with the sealing liner 94. The sealing 94 creates a seal betweenthe exterior surface of the main liner member 30 and the interior wallof the pipe 14. The main liner member 30 and sealing liner 94 can bemoved through the pipe 14 together, as shown in FIG. 15. Those skilledin the art having the benefit of this disclosure will appreciate thatthe sealing member can also be used in lateral or main line piperepairs, and not necessarily main/lateral junction repairs. In suchcases, the sealing liner 94 can be inverted with a tubular liner as partof a liner/bladder assembly. Still further yet, the sealing liner 94 canbe first moved into position adjacent the damaged area of pipe and atubular liner saturated with resin later everted or otherwise insertedinto the sealing member. The sealing member 94 is pressed against theinterior of the host pipe between the host pipe and the tubular linersaturated with resin. In this arrangement there is no resin to adherethe main liner member 30 directly to the main pipe 14. However, theresin on the main liner member 30 cures to form a rigid structure, andwhere the main liner member 30 forms an interior lining of the main pipe14.

FIGS. 8-12 show various other alternative embodiments for themain/lateral liner assembly. FIG. 8 shows a main/lateral liner assembly80 that comprises a lateral liner tube 28 and a main liner member 82shaped in the form of a collar. This configuration is typically referredto as a “top hat” liner in the industry. As distinguished from a typical“top hat”, the main/lateral liner assembly 80 in FIG. 8 includes acollar 82 formed from the same non-resin absorbent material with anuneven exterior surface as previously disclosed. The collar 82 onlyhelps to seal the area around the opening to the lateral sewer pipe 14,and does not line the full circumference of the main sewer pipe 16.

Another alternative embodiment of the main/lateral liner assembly isshown in FIG. 9. Here, the main/lateral liner assembly 84 includes thesame lateral liner tube 28 and collar 82 of non-resin absorbentmaterial. A secondary main liner member 86 extends from the periphery ofthe collar 82. The secondary main liner member 86 is a resin absorbentfelt material with plastic coating similar in construction to thelateral liner tube 28. Because the highest pressures are applied to themain/lateral liner assembly 84 near the juncture between the laterallining tube 28 and the main liner portion, using only a collar ofnon-resin absorbent material with a felt liner extending therefromallows for a full circumference wrap on the interior wall of the mainsewer pipe 16 while minimizing the cost associated with a full sheet ofnon-resin absorbent material. In addition, a full circumference wrapprovides structural support against hydraulic loading and helps ensurethat the collar 82 will not fall away if disbanding occurs.

Another alternative embodiment is shown in FIG. 10. Here, themain/lateral liner assembly 88 includes a lateral liner tube 28 and amain liner member 30 as previously disclosed. What is different is thata tubular section 90 of non-resin absorbent material with the sameuneven exterior surface as on the main liner member 30 extends above themain liner member 30 around the main liner opening, which thentransitions to the lateral liner tube 28. This embodiment helps avoidthe situation where the end of the lateral liner tube 28 has a reducedthickness caused by excess fluid pressures applied during the eversionprocess. The embodiment shown in FIG. 10 can be further modified suchthat tubular section 90 extends further into the lateral pipe 14,avoiding the need for a separate lateral liner tube 28 that is resinabsorbent. Both the main and lateral portions of main/lateral linerassembly 88 would be made from a non-resin impregnable material withuneven exterior surfaces or apertures adapted to receive resin.

FIG. 11 is a sectional view that illustrates another alternativeembodiment of the main/liner assembly. The liner assembly is formedusing a lateral liner tube 28 and main liner member 31 made of felt. Aring or donut 91 of non-resin absorbent material having an unevenexterior surface is positioned on top of the main liner member 31 aroundthe lining junction between the main liner member 31 and the laterallining tube 28. The lateral liner tube 28 is threaded through the ring91. Although the ring 91 need not be permanently attached, it isdesirable to permanently attach the ring to the main liner tube 31. Thering 91 may be held in place by resin or other means, such as snaps,stitching, stapling, welding and similar means.

FIG. 12 illustrates yet another alternative embodiment of themain/lateral lining assembly. Instead of a donut 91 positioned on top ofthe main liner member 31, a “top hat” or gasket 92 of thermoplasticmaterial having protrusions and depressions on the exterior surface ispositioned over a portion of both the main liner member 31 and thelateral liner tube 28. This embodiment has the advantage of providingextra protection along the lateral liner tube 28 at the juncture betweenthe lateral sewer pipe 14 and the main sewer pipe 16.

This detailed description is of exemplary embodiments and variousmodifications and variations are contemplated. For example, themain/lateral liner assemblies described above may be installed in thehost pipes by using a one-piece main and lateral bladder or two separatebladders may be used. The lateral lining may be open ended with abladder extending beyond the lateral lining at the upper most end of thelateral lining or the lateral lining may be closed, requiring cutting.The lateral lining may also be installed using a bladderless typeapplication, such as disclosed in pending application Ser. No.12/026,209, the contents of which are incorporated herein by reference.

1. An apparatus for repairing a damaged portion of a pipe with aninterior wall, the apparatus comprising: a lining formed from anon-resin absorbent material having an interior surface and an exteriorsurface, the exterior surface being uneven and adapted to receive acurable resin that contacts the interior wall of the pipe.
 2. Theapparatus of claim 1 wherein the exterior surface includes an irregularpattern of raised areas with spaces there between.
 3. The apparatus ofclaim 1 wherein the material forming the lining is a thermoplastic orthermoset material.
 4. The apparatus of claim 3 wherein the material ispolyurethane or polyvinyl chloride.
 5. The apparatus of claim 1 whereinthe lining tube has a wall thickness of approximately greater than 50mils.
 6. The apparatus of claim 1 wherein the lining is tubular in shapeand the apparatus further comprises at least two compressible bandsspaced apart and surrounding the lining tube, the compressible bandscapable of forming a seal between the exterior surface of the liningtube and the interior wall of the pipe.
 7. An apparatus for repairing adamaged portion of a pipe with an interior wall, the apparatuscomprising: a lining tube formed from a non-resin absorbent material andhaving an exterior surface adapted to receive a curable resin forsecuring the liner tube to the interior wall of the pipe; and acompressible member positioned on the exterior surface of the liningtube and being adapted to form a seal between the exterior surface ofthe lining tube and the interior wall of the pipe.
 8. The apparatus ofclaim 7 wherein the lining tube includes a plurality of aperturesadapted to receive the curable resin.
 9. The apparatus of claim 7wherein the material for the non-resin absorbent material is athermoplastic or thermoset material.
 10. The apparatus of claim 7wherein the lining tube has a wall thickness of approximately greaterthan 50 mils.
 11. The apparatus of claim 7 wherein the exterior surfaceof the lining tube being adapted to mechanically bond the resin to thelining tube after the resin cures and hardens about the exterior surfaceof the lining tube.
 12. The apparatus of claim 11 wherein the exteriorsurface of the lining tube includes projections adapted to mechanicallybond the resin to the lining tube after the resin cures and hardensabout the exterior surface of the lining tube.
 13. The apparatus ofclaim 11 wherein the exterior surface of the lining tube includeshooklike projections adapted to mechanically bond the resin to thelining tube after the resin cures and hardens about the exterior surfaceof the lining tube.
 14. The apparatus of claim 7 wherein thecompressible member includes first and second hydrophilic bands spacedapart and surrounding the lining tube, the first and second hydrophilicbands being capable of swelling in response to being exposed to aliquid, thereby forming a seal between the exterior surface of thelining tube and the interior wall of the pipe.
 15. The apparatus ofclaim 7 wherein the compressible member forms a tube of hydrophilicmaterial that surround at least a portion of the lining tube, the tubecapable of swelling in response to being exposed to a liquid, therebyforming a seal between the exterior surface of the lining tube and theinterior wall of the pipe.
 16. A liner assembly for repairing a damagedjunction between a main pipe and a lateral pipe comprising: a main linermember having a main liner member opening and formed from a non-resinabsorbent material having an exterior surface adapted to receive acurable resin that contacts an interior wall of the main pipe; and aresin absorbent lateral liner tube extending from the main liner memberabout the main liner member opening and adapted to extend within thelateral pipe and contact an interior wall of the lateral pipe.
 17. Theliner assembly of claim 16 wherein the main liner member forms a collar.18. The liner assembly of claim 16 wherein the main liner member forms atube.
 19. The liner assembly of claim 16 wherein the exterior surfaceincludes a plurality of protrusions with spaced areas there between. 20.The liner assembly of claim 16 wherein the exterior surface of the mainliner member being adapted to mechanically bond the resin to the mainliner member after the resin cures and hardens about the exteriorsurface of the main liner member.
 21. The liner assembly of claim 20wherein the exterior surface of the main liner member includesprojections adapted to mechanically bond the resin to the lining tubeafter the resin cures and hardens about the exterior surface of the mainliner member.
 22. The liner assembly of claim 20 wherein the exteriorsurface of the main liner member includes hooklike projections adaptedto mechanically bond the resin to the lining tube after the resin curesand hardens about the exterior surface of the main liner member.
 23. Theliner assembly of claim 16 wherein the lateral liner tube is flaribleand adapted to conform to the interior wall of the lateral pipe.
 24. Theliner assembly of claim 16 further comprising a secondary main linermember of resin absorbable flexible material extending from a peripheryof the collar and adapted to form a tubular structure with the collarand conform to the interior wall of the main pipe.
 25. The linerassembly of claim 16 wherein the non-resin absorbent material is athermoplastic or thermoset material.
 26. The liner assembly of claim 18further comprising a compressible member surrounding at least a portionof the main liner member and being adapted to form a seal between theexterior surface of the main liner member and the interior wall of themain pipe.
 27. The liner assembly of claim 26 wherein the compressiblemember is a hydrophilic member being capable of swelling in response tobeing exposed to a liquid, thereby forming a seal between the exteriorsurface of the main liner member and the interior wall of the main pipe.28. A liner assembly for repairing a damaged pipe junction between amain pipe and a lateral pipe comprising: a resin absorbable main linermember and a resin absorbable lateral liner tube in communication withone another through a liner juncture, the lateral liner tube beingadapted to extend within the lateral pipe and the main liner memberbeing adapted to extend within the main pipe near the pipe junction; anda collar disposed on the main liner member around the liner juncture,the collar formed from a non-resin absorbable material having an unevenexterior surface adapted to receive a curable resin that contacts aninterior wall of the main pipe.
 29. The liner assembly of claim 28wherein the collar further comprises a tubular portion surrounding aportion of the lateral liner and adapted to contact an interior wall ofthe lateral pipe.
 30. The liner assembly of claim 28 wherein the mainliner member is formed in the shape of a tube.
 31. An apparatus forrepairing the junction of a main pipe and a lateral pipe connectedthereto, comprising: a main bladder tube and a lateral bladder tube; amain liner member having a main liner member opening and formed from anon-resin absorbent material having an exterior surface adapted toreceive a curable resin; a lateral lining tube of resin absorbentmaterial extending from the main liner member about the main linermember opening; a launcher device having first and second opposite endsand a launcher device opening there between; the main bladder tube beingoutside and surrounding the launcher device and the lateral bladder tubeextending through the launcher device opening and into the inside of thelauncher device; and the main liner member being outside and at leastpartially surrounding the main bladder tube and the launcher device, thelateral liner tube extending through the launcher device opening andinto the inside of both the launcher device and the lateral bladdertube.
 32. The apparatus of claim 31 wherein the exterior surface of themain liner member includes a plurality of spaced-apart raised areas. 33.The apparatus of claim 31 wherein the main liner member is formed in theshape of a tube.
 34. The apparatus of claim 33 further comprising ahydrophilic member disposed on the exterior surface of the main linermember.
 35. The apparatus of claim 31 wherein the non-resin absorbentmaterial is a thermoplastic or thermoset material.
 36. A method ofrepairing a damaged pipe junction between a main pipe and a lateralpipe, the method comprising: providing a liner assembly including a mainliner member having a main liner member opening and formed from anon-resin absorbent material having an exterior surface adapted toreceive a curable resin, and a lateral lining tube of resin absorbableflexible material extending from the main liner member about the mainliner member opening; applying a resinous material capable of curing andhardening to the exterior surface of the main liner member; impregnatingthe lateral liner tube with a resinous material capable of curing andhardening; moving the liner assembly through the main pipe to anoperative position with the main liner member adjacent the pipejunction; pressing the main liner member against an interior wall of themain pipe; inserting the lateral lining tube into the lateral pipe; andpressing the lateral lining tube against an interior wall of the lateralpipe.
 37. The method of claim 36 wherein the lateral liner tube iseverted into the lateral pipe.
 38. The method of claim 36 wherein thelateral liner tube is pulled into the lateral pipe.
 39. The method ofclaim 36 wherein the exterior surface of the main liner member isuneven.
 40. The method of claim 36 wherein the main liner member forms atube and the liner assembly further comprises a compressible memberdisposed on the main liner member and being adapted to form a sealbetween the exterior surface of the main liner member and the interiorwall of the main pipe.
 41. The method of claim 40 wherein thecompressible member is a hydrophilic member disposed on the main linermember, wherein the hydrophilic member is pressed against the interiorwall of the main pipe line between the exterior surface of the mainliner member and the interior wall of the main pipe.
 42. A method forrepairing a damaged section of pipe, comprising: providing a lining tubeformed from a non-resin absorbent material having an interior surfaceand an exterior surface, the exterior surface having raised areas andadapted to receive a curable resin; applying a resinous material capableof curing and hardening to the exterior surface of the lining tube;moving the liner tube through the pipe adjacent the damaged section; andpressing the liner tube against an interior wall of the pipe.
 43. Themethod of claim 42 further comprising the step of positioning at leasttwo compressible bands spaced apart and surrounding the liner tube andwherein the compressible bands are pressed against the interior wall ofthe pipe between the exterior surface of the liner tube and the interiorwall of the pipe on opposite sides of the damaged section of pipe. 44.The method of claim 43 wherein the compressible bands are hydrophilicbands.
 45. The method of claim 42 wherein the exterior surface of thelining tube is irregular.
 46. A liner assembly for repairing a damagedjunction between a main pipe and a lateral pipe comprising: a main linermember having a main liner member opening and formed from a non-resinabsorbent material having a smooth interior surface and an exteriorsurface with a plurality of protrusions adapted to receive a curableresin that contacts an interior wall of the main pipe; a lateral linertube extending from the main liner member opening and having an exteriorsurface adapted to receive a curable resin that contacts an interiorwall of the lateral pipe; a compressible sealing member positioned atleast partially on the main liner member.
 47. The liner assembly ofclaim 46 wherein the compressible sealing member is a sheet of materialsurrounding a portion of the main liner member on opposite sides of themain liner member opening.
 48. The liner assembly of claim 46 whereinthe compressible sealing member is a collar disposed on the main linermember around the main liner member opening.
 49. The liner assembly ofclaim 48 wherein the collar further comprises a tubular portionsurrounding a portion of the lateral liner and being adapted to contactan interior wall of the lateral pipe.
 50. The liner assembly of claim 46wherein the lateral liner tube is formed from a resin-absorbentmaterial.
 51. The liner assembly of claim 46 wherein the compressiblereading member is hydrophilic.
 52. A method of repairing a damagedsection of pipe comprising: providing a liner formed from a non-resinabsorbent material having an interior surface and an exterior surface;applying a putty capable of curing to the exterior surface of the liner;moving the liner though the pipe adjacent the damaged section of pipe;and pressing the liner against an interior wall of the pipe wherein theputty contacts the pipe.
 53. A method of repairing a damaged section ofa pipe having an interior wall, the method comprising: providing a linerassembly including an elongated tubular liner of resin absorbentmaterial having an interior surface and an exterior surface and acompressible member extending about the exterior surface of the liningtube along substantially the length of the tubular liner; applying aresinous material capable of curing and hardening to the tubular liner;positioning the liner assembly inside the pipe adjacent the damagedsection of pipe; and pressing the liner assembly against the interiorwall of the pipe with the compressible material creating a seal betweenthe exterior surface of the tubular liner and the interior wall of thepipe.
 54. The method of claim 53 wherein the liner assembly is evertedin the pipe.
 55. The method of claim 53 wherein the liner assembly ispulled into the pipe.
 56. The method of claim 53 wherein thecompressible member is a hydrophilic member capable of swelling inresponse to being exposed to a liquid.
 57. A method of repairing adamaged section of a pipe having an interior wall, the methodcomprising: providing an elongated tubular liner of resin absorbentmaterial having an interior surface and an exterior surface; providingan elongated tubular sealing liner of compressible material; insertingthe tubular sealing liner into the pipe adjacent the damaged section ofthe pipe; impregnating the tubular liner with a resinous materialcapable of curing and hardening; inserting the tubular liner saturatedwith the resinous material into the sealing liner; and urging thetubular liner and the sealing liner toward the interior wall of the pipewith the sealing liner pressed against the interior wall of the pipe andcreating a seal between the exterior surface of the tubular liner andthe interior wall of the pipe.
 58. The method of claim 57 wherein thesealing liner is made of a hydrophilic material capable of swelling inresponse to being exposed to a liquid.